Once activated, all tears in the air split into 6 more tears in all directions, which retain their damage and shot speed.
Luck-based effects from items such as Tough Love or Holy Light are applied individually to each tear.
Notes
The item only costs 10 coins when found in a Shop.
Synergies
Akeldama: Will bust tears generated by Akeldama into Isaac's current tears.
Angelic Prism: Tears that are split by the prism can be split again by Tear Detonator.
Anti-Gravity: All tears currently floating in the air will be multiplied, resulting in a massive amount of tears.
Bethany/Tainted Bethany: Bethany can use Tear Detonator multiple times in rapid succession at the cost of one Soul/Blood Charge per use, allowing for a huge area of effect that wipes out most rooms.
Book of Virtues: Spawns wisps on the middle ring. The wisps' tears are also detonated into 6 tears; the resulting tears are based on Isaac's own, rather than the wisps'. Created wisps trigger Tear Detonator's effect when destroyed. Despite Tear Detonator having a timed recharge, the wisps persist between rooms.
Car Battery: Multiplies the tears, creating 6×6= 36 tears for every tear currently airborne.
The Battery: Can multiply the tears again,and by theory it can create 36×6×6= 1296 tears in total.(not sure if this actually works can somebody test it out please)
Eye of the Occult: Split tears form a circle around the original tear's position, and can be controlled as normal.
Haemolacria: Splits tears into 6 Haemolacria tears that burst into split tears. If split tears are burst, all of them will split into 6 Haemolacria tears creating an enormous amount of tears when the main tear splits again.
Ipecac: All tears will split into 6 explosive tears, making it very powerful (but also dangerous unless Isaac has Host Hat or Pyromaniac).
Lachryphagy: Similar to the Haemolacria synergy, if the main tear splits, 6 tears will spawn that can be fed. However, if burst tears are split, all burst tears will split into 6 tears resulting in an enormous amount of tears that are likely to feed each other.
Lead Pencil: Each of the tears explodes into 6 smaller tears.
The Ludovico Technique: The tear explodes into six smaller tears, then reappears next to the player.
My Reflection: The shrapnel tears will curve back to the location of the original detonated tear.
Chocolate Milk: No matter how charged the tears are, split tears always deal a tiny amount of damage.
Split tears always deal Isaac's damage.
Explosivo: Tears that are stuck to enemies will not deal explosion damage; tears released by it may be sticky tears that immediately stick back onto the enemy.
No Effect
Tear Detonator becomes useless with the following, barring other sources of tears:
Tough Love or 
Holy Light are applied individually to each tear.
The item only costs 10 coins when found in a 
Shop.
Akeldama: Will bust tears generated by Akeldama into Isaac's current tears.
Angelic Prism: Tears that are split by the prism can be split again by Tear Detonator.
Anti-Gravity: All tears currently floating in the air will be multiplied, resulting in a massive amount of tears.
Bethany/ 
Tainted Bethany: Bethany can use Tear Detonator multiple times in rapid succession at the cost of one Soul/Blood Charge per use, allowing for a huge area of effect that wipes out most rooms.
Book of Virtues: Spawns wisps on the middle ring. The wisps' tears are also detonated into 6 tears; the resulting tears are based on Isaac's own, rather than the wisps'. Created wisps trigger Tear Detonator's effect when destroyed. Despite Tear Detonator having a timed recharge, the wisps persist between rooms.
Car Battery: Multiplies the tears, creating 6×6= 36 tears for every tear currently airborne.
The Battery: Can multiply the tears again,and by theory it can create 36×6×6= 1296 tears in total.(not sure if this actually works can somebody test it out please)
Circle of Protection / 
Metal Plate: Reflected tears can be split.
Compound Fracture/
Cricket's Body/
The Parasite: Tears that are split can split again into burst tears.
Eye of the Occult: Split tears form a circle around the original tear's position, and can be controlled as normal.
Haemolacria: Splits tears into 6 Haemolacria tears that burst into split tears. If split tears are burst, all of them will split into 6 Haemolacria tears creating an enormous amount of tears when the main tear splits again.
Ipecac: All tears will split into 6 explosive tears, making it very powerful (but also dangerous unless Isaac has 
Host Hat or 
Pyromaniac).
Lachryphagy: Similar to the Haemolacria synergy, if the main tear splits, 6 tears will spawn that can be fed. However, if burst tears are split, all burst tears will split into 6 tears resulting in an enormous amount of tears that are likely to feed each other.
Lead Pencil: Each of the tears explodes into 6 smaller tears.
The Ludovico Technique: The tear explodes into six smaller tears, then reappears next to the player.
My Reflection: The shrapnel tears will curve back to the location of the original detonated tear.
Sad Bombs: Bomb tears are multiplied.
Saturnus: Orbiting tears can be split, including enemy tears caught in the orbit.
Technology Zero: Tears generated by Tear Detonator can be connected with electric charges.
Mucormycosis / 
Sinus Infection: Spores/Boogers generated by Tear Detonator can be connected with electric charges.
Tiny Planet: Tears split, and then orbit around where the tear was originally from, three spinning clockwise, three counterclockwise.
Trisagion: Tears split into six beams.
C Section: Fetuses split into normal tears.
Chocolate Milk: No matter how charged the tears are, split tears always deal a tiny amount of damage.
Explosivo: Tears that are stuck to enemies will not deal explosion damage; tears released by it may be sticky tears that immediately stick back onto the enemy.
Azazel
Brimstone
Dr. Fetus
Epic Fetus
Mom's Knife
Tech X
Technology
Technology 2(laser only)
Remote Detonator, but colored blue.
The Binding of Isaac: Rebirth
